In the exercise field, there are numerous devices designed to help a user improve his or her grip strength and the muscles of the wrist and forearm. These devices usually can be classified in one of two categories. In the first category is the type of device that fits within a user's hand and is squeezed by the user. In the second category is the type of hand exerciser that has one or more springs or elastic bands attached to a base. In the latter type of device, the user attempts to stretch the springs/bands with his or her fingers.
The squeezable type of device is typified by a ball or an ergonomically-shaped grip that the user can hold within a hand. Common rubber balls have been used as exercise grips for many years with varied amounts of success. The ergonomically-shaped grips normally include a shaped body that has indentations along a forward edge to partially receive each of a user's long fingers.
The squeezable grips are manufactured from a rubber material that is fully resilient. The inherent resiliency of the material causes the grip to fully recover its original shape after being deformed by the user's hand. Once the user has the grip within his or her hand, the user exercises by repeatedly squeezing and then releasing the grip. While exercising, the grip is normally maintained in a single position without any rotation caused by the user's fingers.
The second type of exercise device normally includes a rigid, elongated base and a plurality of spacedly attached springs or elastic bands that are individually connected to the fingers of one of the user's hands. The user places his or her hand onto the device and uses his or her fingertips to stretch the springs or elastic bands. When the user stops applying force, the springs or elastic bands return to their original length.